What is Hazard and Operability (HAZOP)?
Hazard and Operability Study also known as HAZOP is a structured and systematic method used to identify potential hazards and operability problems in a process or system. It is normally carried out by a competent and dedicated team. It was one of the method for Process Hazard Analysis (PHA).
HAZOP normally studies and identifies any potential deviations from the design intend, examines their possible causes and assessing the consequences. HAZOP methodology uses guide words as way to systematically assessing the process or system. These guide words are combination of the deviations (No, Less, More, As Well As, Part Of, Reverse, Other Than & etc.) and the parameters (Flow, Tempreature, Pressure, Level & etc.).
As per CCPS definition, a HAZOP is a systematic qualitative technique to identify process hazards and potential operating problems using a series of guide words to study process deviations. It was used to question every part of a process to discover what deviations from the intention of the design can occur and what their causes and consequences may be. This is done systematically by applying suitable guidewords. This is a systematic detailed review technique, for both batch and continuous plants, which can be applied to new or existing processes to identify hazards.
Why Do We Need HAZOP?
We need to perform HAZOP as part of the Process Hazard Analysis (PHA) and risk assessment requirements.
When to Perform HAZOP?
We need to perform HAZOP to examine the deviations from the design requirements and intents.
How to Perform HAZOP?
HAZOP can be performed by the following steps:
- Define the Scope & Objectives – Establish the boundaries of the study, including the system or process to be analyzed.
- Form the HAZOP Team – Assemble a multidisciplinary team of experts, including engineers, operators, and safety professionals.
- Break Down the System into Nodes – Divide the process into manageable sections (nodes) for detailed analysis.
- Identify Process Parameters – Examine key variables such as temperature, pressure, flow rate, and chemical composition.
- Apply Guide Words – Use predefined keywords like “More,” “Less,” “Reverse,” or “None” to explore potential deviations.
- Analyze Causes & Consequences – Determine the root causes of deviations and assess their impact on safety and operations.
- Evaluate Safeguards – Identify existing control measures and determine if additional safety mechanisms are needed.
- Document Findings & Recommendations – Record observations and propose corrective actions to mitigate risks.
- Review & Implement Changes – Ensure that recommended improvements are applied and periodically reassessed.